Most of the students sat down thinking magistrates were old and out of touch; Barbara Jones and Phil Perry needed less than an hour to change their minds.
Before an audience of 50 sixth-formers and a handful of tutors, the two of them orchestrated a mock trial and explained their role as justices of the peace with coolness and clarity.
They were visiting the Bulmershe School in Reading, an 11-18 comprehensive, under the auspices of the Magistrates' Schools Project. The five-year-old scheme is designed to broaden children's understanding of the magistrate system, which handles 97 per cent of all criminal cases.
It took a while to get off the ground, but the project now involves 3, 000 JPs (about 10 per cent of the national total) visiting, in pairs, some 6,000 schools all over England and Wales. It was devised by Rosemary Thomson, chair of the Magistrates' Association, and Richard Grobler, of the Lord Chancellor's Department.
Barbara Jones became a magistrate after she was "enthralled" by jury duty, and has been touring the local education circuit for four of her ten years on the Reading and Sonning Petty Sessional Division. Phil Perry became a JP in 1992, after retiring early from business.
The Bulmershe students' answers to questions at the start of the lecture illustrate why the association feels the magistracy's work is widely misunderstood. Only one of the 50 teenagers had observed cases at Reading magistrates court. All of them wrongly assumed that JPs are paid. None knew that you become eligible for the magistracy at the age of 27.
None the less, when the mock trial of "shoplifter" Margaret Jones (played by Heidi Craske, daughter of a WPC) opened at the front of the hall, they proved diligent and fair judges. Six students read the parts of defendant, witnesses, solicitors and court clerk.
Jones, a classroom assistant at a local primary school, denied stealing a children's cardigan worth Pounds 8.99 from Marks Spencer. The Crown Prosecution Service solicitor told the court how Jones had stuffed the cardigan into a shopping bag, then paid for a pair of children's trousers and left, before being apprehended by a store detective.
After the prosecution case, a short break gave the 14 benches (with three student JPs on each, as in a real court) a chance to deliver a "half-time" verdict. All 14 were ready to find the defendant guilty. Perry explained: "The break shows that when we've heard the prosecution, we often can't imagine how the defendant could possibly be innocent. But then he or she changes our minds." So it proved.
Jones explained that the cardigan must have somehow slipped from her grasp. At her wits' end after five hours of shopping with her seven-year-old daughter, she had not realised she was only paying for the trousers. She had never been in any criminal trouble before.
Four benches believed her ("I know what it's like when you're with a stroppy kid"), but ten said "guilty" again ("If you've got a kid, then money's tight and you'd know you were paying too little").
After Barbara Jones and Perry had shown them the official sentencing guidelines, the majority of the benches handed down conditional discharges of between six and 12 months, some adding fines ranging from Pounds 20 to Pounds 100. "That's about right for a first offence involving an item of low value, " Perry said. "But I've visited schools where the pupils are much more 'hang 'em and flog 'em' than here; more so than any magistrates I know."
The Jones case is fictional, but the story is heard thousands of times in real courts. Perry describes it as "a cracker" for engaging a school audience, "because all of us swiped a sweet from the pick 'n' mix as kids, or have at least been tempted to shoplift". His hope at the start of every lecture is that pupils will realise that magistrates are not "a bunch of stuffed shirts, but ordinary local people dispensing local justice", and reactions at Bulmershe suggested a mission accomplished.
Steven Wilson spoke for many when he said: "I thought they would be really, really old (Perry is 49, Jones 58) and I didn't expect them to be so nice. " Harleen Kaur said: "I think magistrates must be able to understand the problems that ordinary people face - like not having much money to buy clothes for your kid - in a way that judges can't."
Dr Gill Grainger, head of the Bulmershe sixth form, said she and her colleagues would be picking up the lecture in a number of subjects. "We'll develop it for A-level sociology, and the courts are an important element in the health and social care syllabus." The magistrates' visit was part of a weekly lecture programme that includes a number of other talks dealing with students' responsibilities to their fellow citizens (representatives from Oxfam and Amnesty International were next up).
Dr Grainger said that the ever-increasing range of vocational and academic courses offered to the 250 post-16 students at Bulmershe meant that general studies slots had almost disappeared from the timetable. "That's why lectures like this are so valuable. They are a rallying point for the sixth form. "
The Magistrates' Association can be contacted on 0171 387 2353